Policy and Charging Control (PCC) includes a policy server, such as PCRF (Policy and Charging Rule Function), and a policy enforcement function, such as PCEF (Policy and Charging Enforcement Function) or TDF (Traffic Detection Function). The policy enforcement function performs deep packet inspection to detect the application traffic (e.g., inspecting the traffic of applications such as facebook, google email, and the like) or performs dynamic QoS and charging control. The policy enforcement function is also connected to a charging system and a subscriber database, to help operators dynamically control the way the subscribers and applications consume data network resources. A policy decision can be based on a wide variety of triggers, including a subscriber's data volume usage, service tier, location information, application, URL, source IP address, time of day, congestion level and so on. The PCC architecture is a now well established in 4G LTE EPC core network.
Specifically, considering the deployment of a software-defined network (SDN), packet forwarding is separated from control function. The control function is separated from a dedicated network device and enforced by a central “container,” e.g., SDN controller. The SDN controller will tell a packet forwarding device how to transmit application data flows using a standard protocol, such as OpenFlow protocol. A key objective of SDN is to facilitate network development and application virtualization.
The deployment of policy control and subsequently new emerging SDN raise some important issues for how carriers control the way service are supported and delivered to an end user. The current network service deployment models are relatively static, and bound to topology for insertion and policy selection. Furthermore, they are not adapted well to elastic service environments enabled by virtualization.